The present invention relates to a method and apparatus for the detection, measurement, and general evaluation of minute strains in a wide variety of objects, including animal muscle fibers, integrated electronic circuit chips, composite materials and other specimens which thus far have defied appraisal on a micro and sub-micro scale.
The a prior characterization of stress in any given material is essentially impossible to attain. Accordingly, this invention provides an inspection method which is, optionally, dependent on a preselected radiation phase, or amplitude, or a wide choice of combined phase and amplitude simultaneously. In this way a repetitive inspection method, for any given structure in examination, is speedily resolved and means for comparative analysis afforded.